From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39855C433EF for ; Mon, 18 Jul 2022 18:01:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235160AbiGRSBj (ORCPT ); Mon, 18 Jul 2022 14:01:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234225AbiGRSBh (ORCPT ); Mon, 18 Jul 2022 14:01:37 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA4912E6A1; Mon, 18 Jul 2022 11:01:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=fvDvYNh033IOlQjqYKmG7DkfegtAnkMbbjHUTcpexCw=; b=Mkf+EnOO5lL4TN07vG/v1CkFSK O9h2x7xk2EK3aIgRnG4AwBANgxMawFV8s5A/9WP9DRo8lxNkhDCVrYA8ELqmaZyJ9O/BfhdRQ8l6Z yzkVB5uAXV5KRLG28A3gtiEPabNpKDH28R8EPRrlO2YFRtqcZO5N+HVYxUYzl3FSi9Dw/olJPlqwn 1Uc5OlexNfAlnU+PPOKLHFEMxTV+gZwXCPmw2oDdrRPJdxVH1xo7cYn/P3YEreDdQ/UUGAfPOjLbe 7HlNRrEailyn6mm3h1EYu94Ii94VpJE9o4I+1ly4EGFJE00+eo1I7vwrZWPfmm5icIJGiT2O3qSB4 jDzo7BsQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:33428) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oDV3j-0001xD-MR; Mon, 18 Jul 2022 19:01:31 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1oDV3i-0002A1-Oo; Mon, 18 Jul 2022 19:01:30 +0100 Date: Mon, 18 Jul 2022 19:01:30 +0100 From: "Russell King (Oracle)" To: Andrew Lunn Cc: Sean Anderson , "David S . Miller" , Jakub Kicinski , Madalin Bucur , netdev@vger.kernel.org, Paolo Abeni , Eric Dumazet , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandru Marginean , Heiner Kallweit , Vladimir Oltean Subject: Re: [PATCH net-next v3 08/47] net: phylink: Support differing link speeds and interface speeds Message-ID: References: <20220715215954.1449214-1-sean.anderson@seco.com> <20220715215954.1449214-9-sean.anderson@seco.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 18, 2022 at 07:28:58PM +0200, Andrew Lunn wrote: > > > I am rather worried that we have drivers using ->speed today in their > > > mac_config and we're redefining what that means in this patch. > > > > Well, kind of. Previously, interface speed was defined to be link speed, > > and both were just "speed". The MAC driver doesn't really care what the > > link speed is if there is a phy, just how fast the phy interface mode > > speed is. > > I'm not sure that is true. At least for SGMII, the MAC is passed the > line side speed, which can be 10, 100, or 1G. The PHY interface mode > speed is fixed at 1G, since it is SGMII, but the MAC needs to know if > it needs to repeat symbols because the line side speed is lower than > the host side speed. ... and passing the SGMII link speed (1G) will break a lot of stuff where the MAC/PCS may need to know the media speed to do the right number of symbol replication. So I don't think we can get away with just saying ->speed is the link speed which will prevent drivers breaking. I don't think it's that simple. Like everything with phylink, all the drivers need to be looked at and tweaked with every damn change, which makes phylink development painfully slow. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!